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United States Patent |
6,263,454
|
Gold
,   et al.
|
July 17, 2001
|
Storage system
Abstract
The present invention relates to storage systems for computer data and
relates particularly to diagnosis of errors and status monitoring of such
a system. The invention provides a system for storing computer data in
which different error messages are generated according to how many times a
specified low-level error has occurred. In the particular embodiment,
different combinations of error messages are generated according to how
many times a particular low-level error has occurred.
Inventors:
|
Gold; Stephen (Bristol, GB);
Lord; Jonathan Conrad (Bristol, GB);
Turner; Philip John (Bristol, GB)
|
Assignee:
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Hewlett-Packard Company (Palo Alto, CA)
|
Appl. No.:
|
888716 |
Filed:
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July 7, 1997 |
Foreign Application Priority Data
Current U.S. Class: |
714/25; 714/30; 714/46 |
Intern'l Class: |
G06F 011/30 |
Field of Search: |
395/800,182.06,182.04,182.02
235/153
360/191
371/13,24
364/900
714/25,30,46
|
References Cited
U.S. Patent Documents
4048481 | Sep., 1977 | Bailey, Jr. et al. | 235/153.
|
4053752 | Oct., 1977 | DeJohn et al. | 714/710.
|
4549295 | Oct., 1985 | Purvis | 371/13.
|
4689767 | Aug., 1987 | Stevenson et al. | 364/900.
|
5200960 | Apr., 1993 | Hamilton | 371/24.
|
5450609 | Sep., 1995 | Schultz et al. | 395/800.
|
5455926 | Oct., 1995 | Keele et al. | 711/4.
|
5463763 | Oct., 1995 | Kubo | 395/182.
|
5463765 | Oct., 1995 | Kakuta et al. | 395/182.
|
5500940 | Mar., 1996 | Skeie | 714/25.
|
5757594 | May., 1998 | Dang et al. | 360/191.
|
5764881 | Jun., 1998 | Yoshida | 395/182.
|
5844919 | Dec., 1998 | Glover et al. | 714/769.
|
Other References
IBM TDB, vol. 37, No. 02B, Feb. 1994, p 241, "Keeping Users Aware of the
Status of an Object Affected by Multiple Program".
IBM TDB, vol. 37, No. 06B, Jun. 1994, pp 499-501, Operating Intervention
Message Management for Tape Drive Displays.
European Search Report; EP 96305388.
|
Primary Examiner: Lee; Thomas
Assistant Examiner: Nguyen; Nguyen Xuan
Claims
What is claimed is:
1. A system for storing computer data comprising:
a storage device having means for reading data from and writing data to
removable media;
and a controller,
wherein the storage device comprises:
means to perform error diagnosis of interactions between the storage device
and the controller and to translate low-level error indicators into a
plurality of high level error conditions;
means to communicate occurrence of these high level error conditions to the
controller to trigger the provision of error messages to the user;
means for communicating different high level error conditions according to
how many times a specified low-level error has occurred.
2. A system according to claim 1, further comprising means for
communicating different combinations of high level error conditions
according to how many times a particular low-level error has occurred.
3. A system according to claim 1, wherein the low-level error indicators
are grouped into functional types and wherein a predetermined sequence of
high level error conditions is communicated according to how many times a
low-level error of the same functional type has occurred.
4. A system comprising means for communicating different high for storing
computer data comprising:
a storage device having means for reading data from and writing data to
removable media; and
a controller,
wherein the storage device comprises:
means to perform error diagnosis of interactions between the storage device
and the controller and to translate low-level error indicators into a
plurality of high level error conditions;
means to communicate occurrence of these high level error conditions to the
controller to trigger the provision of error messages to a user; and
means for communicating different high level error conditions according to
how many times a specified low-level error has occurred and according to
the elapsed time since the storage device was last cleaned.
5. A system according to claim 1, wherein the error messages are
categorized according to severity.
6. A system according to claim 5, wherein error messages are grouped into
three categories of severity.
7. A system according to claim 1, further comprising means for
automatically initiating a predetermined sequence of error recovery steps
according to the high level error conditions identified.
8. A system according to claim 1, wherein error information is developed by
said controller from said error indicators and error status information
indicative of said error information is stored in the storage device in a
standardized format.
9. A system according to claim 1, which is configured so that an occurrence
of high level error conditions is communicated to the controller at
predetermined points in a storage operation.
10. A system according to claim 1 which is configured so that the
occurrence of high level error conditions is communicated to the
controller whenever a new error is indicated by the storage device.
11. A system according to claim 1, wherein the system comprises a plurality
of storage devices.
12. A system according to claim 1, wherein the storage device is a tape
drive.
13. A storage device arranged for operation in a system and having means
for reading data from and writing data to removable media and a
controller, the storage device comprising:
means to perform error diagnosis of interactions between the storage device
and the controller and to translate low-level error indicators into a
plurality of high level error conditions;
means to communicate occurrence of these high level error conditions to the
controller to trigger the provision of error messages to the user; and
means for communicating different high level error conditions according to
how many times a specified low-level error has occurred.
14. A host computer comprising controller means arranged for operation in a
system that includes a storage device having means for reading data from
and writing data to removable media, said host computer further
comprising:
means to perform error diagnosis of interactions between the storage device
and the controller and to translate low-level error indicators into a
plurality of high level error conditions;
means to communicate occurrence of these high level error conditions to the
controller to trigger the provision of error messages to the user;
means for communicating different high level error conditions according to
how many times a specified low-level error has occurred.
15. A computer usable medium having computer readable program code means
embodied in said medium executable by a host computer to perform as a
controller function during the storing of computer data, said host
computer including a storage device having means for reading data from and
writing data to removable media, wherein the computer usable medium
comprises:
means for controlling the host computer to perform error diagnosis of
interactions between the storage device and said controller function and
to translate low-level error indicators into a plurality of high level
error conditions;
means for controlling the host computer to communicate occurrence of these
high level error conditions to the controller function to trigger the
provision of error messages to the user; and
means for controlling the host computer to communicate different high level
error conditions according to how many times a specified low-level error
has occurred.
16. A method for storing computer data comprising the steps of:
reading data from and/or writing data to removable media;
performing error diagnosis on the basis of any low-level error indicators
resulting from said reading and/or writing step;
translating said low-level error indicators into a plurality of high level
error conditions, wherein different high level error conditions result
according to how many times a specified low-level error has occurred; and
triggering the provision of error messages to a user of the system on the
basis of the occurrence of these high level error conditions.
Description
TECHNICAL FIELD
The present invention relates to devices for storing computer data and
relates particularly to diagnostics and status monitoring.
BACKGROUND ART
It is known to provide status monitoring in a disc drive and U.S. Pat. No.
5,450,609 describes one such system in which an array of disc drives
includes a facility for status monitoring and for warning the user of a
problem. The warning facility described is not very different in scope
from the known facility on existing tape drives of a warning light
indicating failure of a backup operation.
DISCLOSURE OF INVENTION
The present invention aims to provide a status monitoring and diagnostic
facility for a storage device which takes account of the fact that the
storage medium is removable and which diagnoses a wider set of error
conditions than simply flagging imminent failure and which also takes
account of the number of occurrences of a particular type of error.
According to the present invention we provide a system for storing computer
data comprising:
a storage device having means for reading data from and writing data to
removable media;
and a controller,
wherein the storage device comprises:
means to perform error diagnosis and to translate low-level error
indicators into a plurality of high level error conditions;
means to communicate occurrence of these high level error conditions to the
controller to trigger the provision of error messages to the user;
means for communicating different high level error conditions according to
how many times a specified low-level error has occurred.
Thus, in systems implementing the present invention, the particular high
level error conditions communicated depend on how many times a relevant
low-level error has occurred. This feature enables the provision of a
succession of different error messages to the user recommending different
actions if an error persists.
The term `low-level error indicator` is intended to cover both error codes
and other relevant triggers generated in the storage device. Low-level
error codes cover items such as unrecoverable read and/or write errors but
there are also other relevant triggers for high level error conditions
such as the rate at which data is being written, data relevant to the
media being used etc. Low-level error indicators are normally generated by
the firmware in the storage device.
The system may be configured so that only one high level error condition is
communicated as a result of the occurrence of a low-level error indicator.
However, very often more than one high level error condition may be
triggered by the occurrence of a low-level error so that the user may
receive a corresponding combination of error messages. In the embodiments
to be described, the system comprises means for communicating different
combinations of high level error conditions according to how many times a
particular low-level error has occurred.
Preferably, the low-level error indicators are grouped into functional
types and a predetermined sequence of high level error conditions is
communicated according to how many times a low-level error of the same
functional type has occurred.
Thus, in the embodiments to be described, the low-level errors are grouped
into broad categories. If successive errors within one of these groups
occur, this triggers different combinations of the high level error
conditions.
In the embodiments to be described, the system comprises means for
communicating different high level error conditions according to the
elapsed time since the storage device was last cleaned. Many error
conditions can be alleviated by running a cleaning cycle and so, in
practice, this is often the first suggested error recovery step.
Preferably, the error messages are categorised according to severity. In
the embodiments to be described there are three categories of severity:
Information, Warning and Critical.
The system may comprise means automatically to initiate a predetermined
sequence of error recovery steps according to the high level error
conditions identified. This feature means that some error recovery or
error prevention steps may automatically be initiated by the controller
rather than the user. One possibility in the case of an autoloader (a
system with a mechanism for automatically loading media into a storage
device), would be an automatic cleaning cycle using specialised cleaning
media.
Preferably, error status information is stored in the storage device in a
standardised format. This feature enables backup software applications to
interface with storage devices from different manufacturers which
implement the present invention. In this way, the invention provides a
technique whereby the way in which errors are detected and categorised for
a particular storage device is device-specific and can be decided by the
device manufacturer but within the context of a standardised scheme which
enables all devices complying with the standardised format to interface
with backup application software from different software providers in
order to provide the user with consistent error indications.
There are different ways in which the controller may receive error
information from the storage device. In one embodiment to be described,
the system is configured so that the occurrence of high level error
conditions is communicated to the controller at predetermined points in a
storage operation. In another embodiment to be described, the system is
configured so that the occurrence of high level error conditions is
communicated to the controller whenever a new error is indicated by the
storage device.
In the embodiments to be described, the storage device is a tape drive, but
the invention applies also to other storage devices with removable media
eg. optical disc drives.
The controller may be backup controller software running on a host
computer. Alternatively the system may be part of network in which the
controller is backup software running on a backup server on the network.
However, the invention is not limited to these alternatives and the
controller may be implemented in software and/or hardware and may be in a
general purpose computer or a dedicated device, whether standalone or
connected to a network. The system may comprise a plurality of storage
devices such as in an autoloader or a coordinated array of storage
devices.
Other aspects and features of the present invention will become apparent
from the following description, claims and drawings.
BRIEF DESCRIPTION OF DRAWINGS
Particular embodiments of the present invention will now be described, by
way of example, with reference to:
FIG. 1 which shows a tape drive connected to a host computer; and
FIG. 2 which shows by way of a functional block diagram the system of FIG.
1.
The invention will also be described, by way of example, with reference to
tables reproduced at the end of this description in which:
Table 1 shows the error conditions relating to particular flags;
Table 2 shows the sequences of error conditions for read-after-write
errors;
Table 3 shows the sequences of error conditions for read errors;
Table 4 shows the sequences of error conditions for hard errors;
Table 6 shows the format of the Log Sense page;
Table 6 shows the format of the Mode Sense page.
BEST MODE FOR CARRYING OUT THE INVENTION, & INDUSTRIAL APPLICABILITY
Referring to FIG. 1, a tape drive 10 is directly connected to a host
computer 12. The tape drive 10 receives data to be backed up from the host
computer 12 and sends saved data back to the host when requested. A
standard SCSI (`Small Computer System Interface`) interface is used to
interconnect the tape drive 10 with the host computer 12.
FIG. 2 is a functional block diagram of the system represented in FIG. 1.
In FIG. 2, the tape drive 10 is arranged to store and retrieve data in
accordance with the digital data storage (DDS) standard format. The tape
drive 10 comprises a host interface unit 21 for interfacing the drive 10
with a host computer 12 via a standard SCSI bus 39. A data formatter 22 in
the tape drive 10 processes user data records and separator marks into and
out of indexed groups, compresses/decompresses data in a known fashion and
effects low-level signal processing, as specified in the DDS format. The
low-level processing converts streams of bytes from the groups into track
signals ready for recording data to tape and reconverts track signals from
tape back into byte streams for reconstructing the groups. The tape drive
10 further comprises a deck 29 of known type comprising electronic
circuitry for controlling recording heads and tape operations for writing
data to and reading data from a tape medium 295. The tape drive 10 also
comprises a tape drive controller 23 for controlling the operation of the
other elements of the drive in response to commands received from the host
12 via the host interface unit 21.
The drive 10, controlled by the tape drive controller 23, is arranged to
respond to SCSI commands from backup software 36 running the host computer
12 to load/unload a tape, to store a data record or separator mark, to
search for selected separator marks or records, and to read back the next
record and to compress/decompress data records. These functions are
standard tape drive functions and, as such, will not be considered in
further detail in this description. For further, more detailed information
on DDS tape drives and the respective data format, the reader is referred
to European Patent Application EP459041A1.
In accordance with the present embodiment, the tape drive controller 23
incorporates further functionality, which a storage device has hitherto
not provided, to support status monitoring and tape drive diagnostics
capabilities. This functionality is provided by appropriate firmware
processes 24 embedded in the tape drive controller 23. Of the processes: a
first process 242 monitors the status of predetermined functions in the
tape drive 10 by receiving low level system status codes returned by the
other elements of the drive during the operation of the tape drive and, in
response, sets flags to indicate possible problems; a second process 244
interprets the flags in a predetermined manner and generates one or more
predetermined high level status or error codes; and a third process 246
prioritizes the high level codes, where more than one code exists, in
accordance with a pre-defined criteria and stores the results in an area
of random access memory (RAM) 25 accessible by the tape drive controller
23. Once stored, the high level codes may be forwarded to the host
computer 12, for example by "polling", as described below in more detail.
The low level codes, the flags, the high level codes and the priority
criteria are also described in detail below.
As also illustrated in FIG. 2, the host computer 12 comprises a standard
computing platform running under the control of an operating system 37
such as Windows NT 4.0. Backup controller software 36, stored in main
memory 31 and running on a central processing unit 35, is a software
process written, for example, in the C.sup.++ programming language. The
backup software 36 is arranged to control the host computer 12 to operate
in accordance with the present embodiment. The operating system 37 of the
host computer 12 includes: a network driver 32 for transmitting and
receiving data, for example in TCP/IP format, to and from a network (not
shown); a display driver 33, such as a video graphics array (VGA) driver,
to transmit display signals to a display screen 38; and a SCSI driver 34,
to transfer commands and data between the host computer 12 and the tape
drive 10. The drivers provided support respective standard hardware
interfaces.
The backup controller software 36 is arranged to control the host computer
12 to retrieve high level status or error codes which have been stored in
the memory 25 from the tape drive 10 by polling the tape drive 10
regularly. Other methods of moving the data from the tape drive 10 to the
host computer 12 are described below. Further, the backup controller
software 36 is arranged to process any received high level status or error
codes and forward to a user appropriate, pre-defined error or action
messages. Such messages may be forwarded for display to the user on the
display screen 38, and/or across a network to a remote network console
(not shown) as necessary.
As mentioned above, the tape drive 10 firmware 24 monitors the status of
predetermined functions in the drive and is configured to generate error
codes to indicate possible problems--these are referred to herein as
`low-level` error codes. For any given tape drive, these low-level error
codes are mapped to `high level` error conditions so that occurrence of a
low-level error condition causes a particular flag or flags to be set. The
specific conditions for any one flag to be set and cleared are
drive-specific and are defined by the drive manufacturer. If a drive
cannot support the recognition of all the flag conditions, then
unsupported flags may remain unset.
Low-level error indicators may be grouped into functional types with a set
of possible low-level error indicator codes being assigned to each group.
The relevant functional types include:
Unrecoverable write error codes;
Unrecoverable read error codes;
Tape management error codes;
Hardware error codes;
Recoverable write error codes;
Recoverable read error codes.
There are also other groups in addition to the above in this embodiment as
will be shown later.
If such grouping is done, then flags may be set according to which type of
low-level error indicator has occurred. For example, all recoverable write
error codes would cause a particular flag to be set, in fact Flag 1 in
Table 1 in this embodiment. This feature relieves the tape drive
manufacturer of the need to define a mapping from every single low-level
error indicator to a particular flag. This feature also facilitates the
setting of different flags depending on how many times a particular type
of low-level error has occurred.
There are 64 flags defined to cover a wide range of error conditions and
these are as shown in Table 1. The column headings in Table 1 are as
follows:
No.--this is simply the flag number;
Flag--this is the name of the flag and indicates the error to which it
relates;
Type--this indicates the seriousness of the error:
"I"=Information: a suggestion to the user;
"W"=Warning: the user is advised to take action. Performance or data may be
at risk;
"C"=Critical!: action should be taken immediately;
Suggested Host Message--this is the text of the message which should be
relayed to the user eg. by display on the screen of the host computer;
Cause--this indicates the cause of the error. Where setting of a flag
depends on a simple true/false criterion, the cause is given in Table 1.
Where setting of a flag depends on the number of times a particular type
of error occurs in a predetermined timeframe, details are given in Tables
2 to 4 (to be described).
If a flag will be set repeatedly on repeated triggering of the specified
cause, this is indicated by `R`. If a flag will not be set repeatedly on
repeated triggering of the specified cause, this is indicated by `NR`.
Cleared--this indicates when the flag is cleared.
The flags are grouped as follows:
Flags 1 to 19: For tape drive write/read management
Flags 20 to 29: For cleaning management
Flags 30 to 39: For tape drive hardware errors
Flags 40 to 49: For tape autoloader errors
Flags 50 to 64: Currently unassigned for future use
Table 2 shows the combinations and sequences of error conditions for
read-after-write errors. When it is more than 24 hours since the tape
drive was last cleaned (State 1), flags 2 and 20 are set on occurrence of
a read-after-write (RAW) error. When it is less than 24 hours since the
tape drive was last cleaned (State 2), flags 2 and 4 are set on occurrence
of a read-after-write (RAW) error.
Table 3 shows the combinations and sequences of error conditions for read
errors. When it is more than 24 hours since the tape drive was last
cleaned, the tape drive is in State 1 and flags 1 and 20 are set on
occurrence of a recoverable read error. If it is less than 24 hours since
the tape drive was last cleaned, the defined state toggles between 1 and 2
as recoverable read errors reoccur. In State 2 flags 1 and 4 are set on
occurrence of a read error.
Table 4 shows the combinations and sequences of error conditions for
unrecoverable (or `hard`) errors. Unrecoverable errors fall into three
groups: bard read errors, hard write errors and hardware errors.
When it is more than 24 hours since the tape drive was last cleaned, the
tape drive is in State 1. If it is less than 24 hours since the tape drive
was last cleaned, the defined state toggles between 1,2 and 3 as hard
errors within the three categories reoccur. The events which trigger state
changes are listed at the bottom of Table 4 as follows:
Cln--performance of a cleaning cycle;
Md Ej--ejection of the current tape cassette;
Soft Reset--performing a soft reboot;
Hard Reset--powering the tape drive off and on again.
For hard read errors (which include certain media-related errors):
State 1 means that flags 3 and 20 are set;
State 2 means that flags 3 and 4 are set;
State 3 means that flags 3 and 5 are set.
For hard write errors:
State 1 means that flags 3 and 20 are set;
State 2 means that flags 3 and 4 are set;
State 3 means that flags 3 and 6 are set.
For hardware errors:
State 1 means that flags 3 and 30 are set;
Subsequent States means that flags 3 and 31 are set.
Alternatively, it may be that soft resets are not a recommended error
recovery step, in which case a hardware error code means that flags 3 and
30 will always be set independently of how many times a hardware error has
occurred.
It can be seen from Tables 2,3 and 4 above that the elapsed time since the
tape drive was last cleaned is relevant to the defined state which in turn
influences which flags are set.
The following is a description of different possible error scenarios and
the error messages that would result, including references to the relevant
ones of Tables 1 to 4 in each case. These scenarios correspond closely to
the functional types of low-level errors mentioned above.
There is a `caution` LED on the tape drive 10 (not shown in FIG. 1) which
is normally lit if there is a problem.
1. DRIVE RECOVERABLE READ PROBLEMS (Table 3)
If the tape drive experiences a severe problem reading, then the yellow
caution LED is lit. Data is still read from the tape without error, but
with loss of capacity. The recommended recovery procedure is to try
cleaning the tape drive, then to try a different piece of media, and
finally if the problem persists to seek technical support.
The first time the error is detected, the following error messages would be
displayed:
WARNING: The tape drive is having problems reading data. No data has been
lost, but there has been a reduction in the capacity of the tape.
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the drive
2. If the operation has not stopped, continue and clean the drive when
finished.
If the error persists, then the next set of error messages to be displayed
is:
WARNING: The tape drive is having problems reading data. No data has been
lost, but there has been a reduction in the capacity of the tape.
CRITICAL: Your data is at risk:
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation with a different tape.
This cycle repeats each time the error condition is detected again.
2. DRIVE RECOVERABLE WRITE PROBLEMS (Table 2)
If the tape drive experiences a severe problem writing, then the yellow
caution LED is lit. Data is still written to the tape without error, but
with loss of capacity. The recommended recovery procedure is to try
cleaning the drive, then to try a different piece of media, and finally if
the problem persists to seek technical support.
The first time the error is detected, the following error messages would be
displayed:
WARNING: The tape drive is having problems writing data. No data has been
lost, but there has been a reduction in the capacity of the tape.
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the drive
2. If the operation has not stopped, continue and clean the drive when
finished.
If the error persists, then the next set of error messages to be displayed
is:
WARNING: The tape drive is having problems writing data. No data has been
lost, but there has been a reduction in the capacity of the tape.
CRITICAL: Your data is at risk:
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation with a different tape.
This cycle repeats each time the error condition is detected again.
3. DRIVE UNRECOVERABLE READ PROBLEMS (Table 4)
If the tape drive experiences an unrecoverable read failure, then the
yellow caution LED is lit and the user's backup job fails. The recommended
recovery procedure is to try cleaning the tape drive, then to try a
different piece of media, and if the problem persists, to seek technical
support.
The first time the error is detected, the following error messages would be
displayed:
WARNING: The operation has stopped because an error has occurred while
reading or writing data which the tape drive cannot correct
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the drive
2. If the operation has not stopped, continue and clean the drive when
finished.
If the error persists, then the next set of error messages to be displayed
is:
WARNING: The operation has stopped because an error has occurred while
reading or writ data which the tape drive cannot correct
CRITICAL: Your data is at risk:
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation with a different tape.
If the error persists, then the next set of error messages to be displayed
is:
WARNING: The operation has stopped because an error has occurred while
reading or writing data which the tape drive cannot correct
CRITICAL: The tape is damaged or the drive is faulty. Call the tape
supplier helpline.
4. DRIVE UNRECOVERABLE PROBLEMS (Table 4)
If the tape drive experiences an unrecoverable write failure, then the
yellow caution LED is lit and the user's backup job fails. The recommended
recovery procedure is to try cleaning the drive, then to try a different
piece of media, and if the problem persists, to seek technical support.
The first time the error is detected the following error messages would be
displayed:
WARNING: The operation has stopped because an error has occurred while
reading or writing data which the tape drive cannot correct
CRITICAL: The tape drive needs cleaning:
1. If the operation has stopped, eject the tape and clean the drive
2. If the operation has not stopped, continue and clean the drive when
finished.
If the error persists, then the same set of error messages is displayed
again:
WARNING: The operation has stopped because an error has occurred while
reading or writing data which the tape drive cannot correct
CRITICAL: Your data is at risk:
1. Copy any data you require from this tape.
2. Do not use this tape again.
3. Restart the operation with a different tape.
If the error persists, then the next set of error messages to be displayed
is:
WARNING: The operation has stopped because an error has occurred while
reading or writing data which the tape drive cannot correct
CRITICAL: The tape is from a faulty batch or the tape drive is faulty:
1. Use a good tape to test the drive.
2. If the problem persists, call the tape drive supplier helpline.
5. DRIVE HARDWARE PROBLEMS (Table 4)
If the tape drive experiences a hardware self-test failure after power-on,
then the yellow caution LED is lit and the backup controller software will
report that the tape drive cannot be used. The recommended recovery
procedure is to try `power cycling` the drive (turning the tape drive off
and then on again). Finally, if the problem persists, technical support
should be sought. The following error message would be displayed:
CRITICAL: The tape drive has a hardware fault:
1. Turn the tape drive off and then on again.
2. Restart the operation.
3. If problem persists, call the tape drive supplier helpline.
6. MEDIA WORN OUT (Table 1)
When the media being used has reached the end of its useful life (maximum
number of passes exceeded) then the data on it should be copied to new
media and the old media discarded. There is normally no user visibility of
media wear, and thus the media will continue being used until it triggers
one of the read/write error conditions. The following error message would
be displayed:
WARNING: The tape cartridge has reached the end of its useful life:
1. Copy any data you need to another tape
2. Discard the old tape.
7. CLEANING TAPE EXPIRED (Table 1)
When the cleaning tape being used wears out, it should be discarded and a
new cleaning tape used if possible. Unless the user is made aware of the
problem, the worn cleaning tape might well continue being used until it
triggers one of the read/write error conditions. To alert the user the
following error message would be displayed:
CRITICAL: The last cleaning cartridge used in the tape drive has worn out:
1. Discard the worn out cleaning cartridge.
2. Wait for the current operation to finish.
3. Then use a new cleaning cartridge.
8. PERIODIC CLEANING REQUIRED (Table 1)
When the tape drive is due for periodic cleaning, a cleaning cycle should
be performed. Unless the user is made aware of the need for a cleaning
cycle, the tape drive might well continue being used until lack of
cleaning triggers one of the read/write error conditions. To alert the
user, the following error message would be displayed:
WARNING: The tape drive is due for routine cleaning:
1. Wait for the current operation to finish.
2. Then use a cleaning cartridge.
9. NON-DATA GRADE MEDIA USED (Table 1)
When the media being used is not data grade, the data stored on it is at
risk. Unless the user is made aware of the problem, the media might well
continue being used until it triggers one of the read/write error
conditions. The user should copy any data they need from the media onto
data grade media and discard the non-data grade media. To alert the user
the following error message would be displayed:
WARNING: The tape cartridge is not data-grade. Any data you back up to the
tape is at risk.
Replace the cartridge with a data-grade tape.
10. ABNORMAL ERROR CONDITIONS (Table 1)
If an abnormal error condition occurs, due to user or backup application
error, then in known systems there will be unexplained failures. One
example is if the backup controller software fails to note that the
cartridge loaded is write protected and thus fails the backup operation.
In a system implementing the present invention, the following error
message would explain this:
CRITICAL: You are trying to write to a write-protected cartridge.
Remove the write-protection or use another tape.
Another example is if the user tries to eject the cartridge when it has
been locked in the drive by the backup controller software. The following
error message would explain why the cartridge was not ejected:
INFORMATION: You cannot eject the cartridge because the tape drive is in
use.
Wait until the operation is complete before ejecting the cartridge.
Also, in the case of an autoloader, the cleaning cartridge may be used in
error for a backup or restore, thus causing unexplained failures. The
following error message would explain this:
INFORMATION: The tape in the drive is a cleaning cartridge.
If you want to back up or restore, insert a data-grade tape.
11. UNSUPPORTED TAPE FORMAT (Table 1)
If a tape cartridge is loaded in the tape drive that is an unsupported
format, it will be automatically ejected by the tape drive. The following
error message would explain why the cartridge was ejected:
INFORMATION: You have tried to load a cartridge of a type which is not
supported by this drive.
The cartridge has been automatically ejected
12. FIRMWARE DOWNLOAD FAILURE (Table 1)
If an attempt is made to download incorrect firmware into the tape drive,
the download will not succeed. The following error message notifies the
user that the firmware download failed:
WARNING: The firmware download has failed because you have tried to use the
incorrect firmware for this tape drive.Obtain the correct firmware and try
again.
13. AUTOLOADER HARDWARE INTERFACE ERROR (Table 1)
In the case of an autoloader, if there is a problem with the tape
autoloader where the tape drive cannot communicate correctly with the
changer mechanism, the autoloader will not function correctly, and the
backup operation fails. The recommended recovery procedure is to try
powering the tape drive off then on again, and finally if the problem
persists to seek technical support. The following error messages would be
displayed:
CRITICAL: The changer mechanism is having difficulty communicating with the
tape drive:
1. Turn the autoloader off and then on again.
2. Restart the operation.
3. If the problem persists, call the tape drive supplier helpline.
14. AUTOLOADER STRAY TAPE (Table 1)
In the case of an autoloader, it is possible for a tape to be left inside
the autoloader after an error, preventing the autoloader from functioning
correctly, and the user's backup operation will fail. The recommended
recovery procedure is to try inserting an empty magazine into the
autoloader, then if the backup operation is still failing, powering the
tape drive off then on again, and finally if the problem persists to seek
technical support. The following error message would be displayed:
CRITICAL: A tape has been left in the autoloader by a previous hardware
fault:
1. Insert an empty magazine to clear the fault.
2. If the fault does not clear, turn the autoloader off and then on again.
3. If the problem persists, call the tape drive supplier helpline.
15. AUTOLOADER MECHANISM HARDWARE ERROR (Table 4, if applicable)
In the case of an autoloader, if there is a problem with the tape
autoloader mechanism/robotics, the autoloader will not function correctly,
and the user's backup operation fails. The recommended recovery procedure
is to try ejecting the magazine, then to try a soft reset (holding down
the eject button for several seconds without a tape loaded in the drive),
then to try powering the tape drive off then on again, and finally if the
problem persists to seek technical support. The first time the error is
detected the following error messages would be displayed:
WARNING: There is a problem with the autoloader mechanism.
CRITICAL:The operation has failed:
1. Eject the tape or magazine.
2. Insert the tape or magazine again.
3. Restart the operation.
If the problem is detected again, then the following error messages are
displayed:
WARNING: There is a problem with the autoloader mechanism.
CRITICAL:The tape drive has a hardware fault:
1. Eject the tape or magazine
2. Reset the drive (hold eject button down for 5 seconds).
3. Restart the operation.
If the problem is detected again, then the following error messages are
displayed:
WARNING: There is a problem with the autoloader mechanism.
CRITICAL:The tape drive has a hardware fault:
1. Turn the tape drive off and then on again.
2. Restart the operation.
3. If the problem persists, call the tape drive supplier helpline.
16. AUTOLOADER DOOR OPEN (Table 1)
In the case of an autoloader, if the door of the autoloader has not closed
correctly after loading a magazine, then the autoloader will not function
and the backup operation fails. The, recommended recovery procedure is to
try closing the door of the autoloader, then if the backup operation is
still failing, powering the tape drive off then on again, and finally if
the problem persists to seek technical support. The following error
message would be displayed
CRITICAL: The operation has failed because the autoloader door is open:
1. Clear any obstructions.
2. Eject the magazine and then insert it again.
3. If the fault does not clear, turn the autoloader off and then on again.
4. If the problem persists, call the tape drive supplier helpline.
The way in which the backup controller software in the host computer 12
interfaces with the tape drive 10 will now be described.
A well-known feature of the standard SCSI interface is the use of `log
sense` pages to record peripheral status information and `mode sense`
pages to record functional and configuration settings.
The error information contained in Table 1 is stored by the tape drive 10
in a `Log Sense` page. The format of the Log Sense page is shown in Table
5. Each line in the Log Sense page represents one byte of data and the
entries are numbered down the lefthand side of Table 5. A description of
the entries is as follows:
Entry 0--the name of the page (2e in this example);
Entry 1--reserved for future use;
Entry 2--the length of the particular page (2 bytes long);
Entry 3--the remainder of the page length;
Entry 4--the SCSI standard uses parameters and this is the name of the
current parameter (2 bytes long). In this embodiment, each parameter
corresponds to one of the flags in Table 1;
Entry 5--the remainder of the parameter name;
Entry 6--the parameter control byte. The fields are explained below. The
terms `sense key` and `sense code` are commonly used in relation to the
SCSI standard to refer to codes for the type of error and details of the
error, respectively:
DU=Disable Update: a value of zero means that the tape drive will not
update the log parameter value (Entry 8 below). A value of one means that
the tape drive will not update the log parameter value except in response
to a Log Select command that specifies a new value for the log parameter.
The DU bit is undefined and ignored if the PC bit (part of the page code)
in the Log Sense command is set to 0.times.00 (as in this embodiment);
DS=Disable Save: a value of zero means that the tape drive supports saving
for that log parameter. A value of one means means that saveable
parameters are not supported;
TSD=Tape drive Save Disable: a value of zero means that the tape drive
provides a tape drive-defined method for saving log parameters. A value of
one means that the tape drive does not provide a tape drive-defined method
of saving log parameters;
ETC=Enable threshold comparison: a value of one means that comparison to
the threshold value is performed. A value of zero means that a comparison
is not performed;
TMC=Threshold Met Criteria: defines the basis for the comparison of the
parameter value. Only valid if ETC=1. If the ETC=1 and the comparison is
true, a check condition will be generated. The Sense key is then set to
UNIT ATTENTION and the additional sense code is set to THRESHOLD CONDITION
MET;
LP=List Parameter: indicates the format of the log parameter. A value of
zero means that the parameter is a data counter. A value of one means that
the parameter is a list parameter, and then the ETC and TMC field must be
set to zero;
Entry 7--the length of the current parameter;
Entry 8--the actual parameter. In this case it is the first flag, namely
the Read Flag. In this embodiment only one bit is used for each flag;
Entry 9 and so on--corresponding entries for the subsequent parameters
(flags). There are two methods by which the host computer 12 can access
error information in the tape drive 10. The first method is "polling"
where the Log Sense page is read from the tape drive at the following
times as a minimum:
1. Immediately after a SCSI Check Condition/Request Sense cycle. This is a
standard cycle in which the drive makes an error status report and if
there is an error this is indicated as a `Check Condition`. The host then
sends a `Request Sense` command to get details of the error.
2. At the end of each tape when the backup/restore job spans multiple
tapes. If the tape is to be ejected then the Log Sense page must be read
before ejection.
3. At the end of a backup/restore job.
It is also recommended to poll the Log Sense page every 60 seconds while
the tape drive is idle.
The second access method is to use the SCSI `Mode Select` command to enable
the "Check Condition" mode, so that the tape drive will report a Check
Condition on the next SCSI a command after one or more flags are set. If
this SCSI command should return a Check Condition due to an actual error,
then this will override the Check Condition `forced` by the Mode Select
command. The Log Sense page will therefore be read from the tape drive
after every Check Condition/Request Sense cycle (both forced check
conditions and error check conditions). The Request Sense extended sense
code (this is the code reported by the tape drive) for a check condition
is 5D00, and the command that triggered this Check Condition will have
been executed, thus the backup controller software will not repeat the
command that triggered a Check Condition.
The recommended method is "check condition" rather than "polling" since
this guarantees that the backup controller software will be made aware of
any flag being set. With "polling" there are theoretical corner-cases
where flag information could be missed, though the higher the polling
frequency the less chance there is of this happening.
The method of access to the tape drive can be configured via the SCSI bus,
based on a new Mode Sense page. The interface can be configured via the
Mode Select command using the same page format to write the configuration
as to read it (Mode Sense command). The format of this new Mode Sense page
is as shown in Table 6.
Again each entry in the Mode Sense page is one byte long. The entries are
as follows:
Entry 0--the name of the page (1C in this example);
Entry 1--the length of the particular page;
The following fields are in the remainder of the Mode Sense page:
DExcpt: When this bit is set to zero the reporting method indicated by the
MRIE field is used. When this bit is set to one this indicates that the
tape drive will ignore the MRIE field (so that the backup controller
software must poll the Log Sense page). Thus to enable "check condition"
mode, this bit must be set to zero.
In this embodiment, the default setting is 1, and this is configurable via
Mode Select
Test: When this bit is set to zero, this indicates that the tape drive will
not generate any false flags. When this bit is set to one, the tape drive
will set a false flag based on the MRIE and Interval Timer flags. Thus the
next SCSI command after the Mode Select command will return Check
Condition, with sense key set to UNIT ATTENTION and extended sense code
set to 5DFF (a test code). If both the Test and DExcpt bits are set to
one, then the Mode Select command will return Check Condition, with sense
key set to Illegal Request and extended sense code set to INVALID FIELD in
the Parameter List.
In this embodiment, the default setting is 0, configurable via Mode Select
Perf: When this bit is set to zero, this indicates that flag setting
operations that can cause delays are acceptable. When this bit is set to
one, the tape drive will not cause delays while setting flags (this may
cause the tape drive to disable some or all of the flag setting
operations).
In this embodiment, the default setting is 0, not changeable via Mode
Select
LogErr: When this bit is set to zero, this indicates that the logging of
flags set within a tape drive is vendor specific. When this bit is set to
one, the tape drive will log flags set.
In this embodiment, the default setting is 0, not changeable via Mode
Select
MRIE: This field indicates the method used by the tape drive to report
flags set. The priority of reporting flags set is tape drive specific. If
the access method being used is the one described above using the Mode
Select command to enable the "Check Condition" mode, so that the tape
drive will report a Check Condition on the next SCSI command after one or
more flags are set then, in the event that the SCSI command should return
a Check Condition due to an actual error, then this will override the
forced Check Condition. The values defined for this field are:
Ox1: No reporting of flags set
Ox2: Generate Unit Attention: tape drive returns Check Condition on the
next SCSI command after a flag is set, with the sense key set to UNIT
ATTENTION and the extended sense code set to 5D00. The command that
triggered the forced Check Condition will not have been executed, and thus
needs to be repeated;
0.times.3: Conditionally generate Recovered Error: depending on the value
of the tape drive error recovery settings, the tape drive returns Check
Condition on the next SCSI command after setting of a flag was detected,
with the sense key set to RECOVERED ERROR and the extended sense code set
to 5D00. The command that has triggered the forced Check Condition will
have been executed correctly, and thus does not need to be repeated;
0.times.4: Unconditionally generate Recovered Error: regardless of the
value of the tape drive error recovery settings, the tape drive returns
Check Condition on the next SCSI command after setting of a flag was
detected, with the sense key set to RECOVERED ERROR and the extended sense
code set to 5D00. The command that has triggered the forced Check
Condition will have been executed correctly, and thus does not need to be
repeated;
0.times.5: Generate No Sense: tape drive returns Check Condition on the
next SCSI command after setting of a flag was detected, with the sense key
set to NO SENSE and the extended sense code set to 5D00. The command that
has triggered the check condition will have been executed correctly, and
thus doe; not need to be repeated;
0.times.6: Only report on request:tape drive will preserve the flag(s) set.
The backup controller software then polls the tape drive using the Log
Sense command.
In this embodiment, the default setting is 3, not changeable via Mode
Select.
Interval Timer. When this field is set to zero, this indicates that the
tape drive will only set a flag once. When this field is set to non-zero,
the value indicates the period in 100 millisecond increments for resetting
a flag. The tape drive will not set flags more frequently than the
specified timer interval and will set flags as soon as possible after the
timer interval has elapsed. A value of 0.times.FFFFFFFF in the field
indicates that the timer interval is tape drive specific.
In this embodiment, the default setting is 0, not changeable via Mode
Select
Report Count: When this field is set to zero, this indicates that there is
no limit to the number of times the tape drive will report a flag being
set (assuming that Interval Timer is set to non-zero). When this field is
set to non-zero, this indicates the number of times to report a flag being
set.
In this embodiment, the default setting is 0, not changeable via Mode
Select.
Every time the Log Sense page is read from the tape drive, the backup
controller software reads all 64 flags to discover which are set (there is
often more than one). There may also be data associated with a set flag in
the remainder of the flag byte, which should also be read. The flags will
automatically be cleared by the tape drive without action from the
software, and thus any set flags read by the backup controller software
indicate a new event. The software therefore will not latch any flag
states but will always action any set flag detected.
A particular backup controller may be connected to more than one tape
drive. In addition, for each tape drive, there will be a plurality of tape
cassettes used for backing up data. Each tape cassette is given a
`software label` to identify it.
For every flag that is set, the backup controller software will log the
error message specified in Table 1 along wit details to identify which
tape drive the error refers to, and the software label of the media for
media related actions (flags 4 and 7). The severity of the error is
identified based on the flag Type field in Table 1.
For every flag that is set, the backup controller software notifies the
user through its normal notification methods (e.g. broadcast, email, SNMP,
etc.), displaying the specified error message along with details to
identify which tape drive the error refers to, and the software label of
the media for media related actions (flags 4 and 7). The notification
identifies the severity of the error, and when multiple flags are set
simultaneously they are listed in ascending order of severity
(Information/Warning/Critical). It is possible to include error message
filters in the backup controller software so that only errors of a certain
severity are notified to the user and/or specifying the mode of
notification of errors of different severity. When multiple flags are set
simultaneously, they may be associated together as a single error event,
for example by displaying all of the associated error messages together in
one dialogue box.
The backup controller software does not fail a backup job based on the flag
information. Rather, setting of the flags provides preventative
maintenance information such that the user or the backup controller
software can initiate actions to prevent the failure occurring at all, and
thus increases the reliability of the backup system. This facility also
provides assistance in diagnosing/recovering a failing backup job.
The backup controller software may be configured to automate the
recommended maintenance/recovery actions, particularly if there are
multiple tape drives or autochangers present. For example, it could
trigger performance of a cleaning cycle for flags 20 and 21, or a tape
copy for flags 4 and 7, and retire the suspect media.
Typically, the backup controller software will be loaded into the memory of
the host computer from a computer readable data carrying medium such as a
floppy disk, mini-disk or optical disk (CD ROM. Alternatively, the
software could be down-loaded accross, a network such as the Internet from
a source such as a World Wide Web or FTP server.
The above embodiment relates to a tape drive but it will be understood that
the present invention is relevant to any storage device which uses
removable media and so is also relevant to optical disc drives.
TABLE 1
No Flag Type Required Host Message Cause Cleared
1 Read W The tape drive is having See
problems reading data. No sub-
data has been lost, but there sequent
has been a reduction in the tables
capacity of the tape.
2 Write W The tape drive is having See
problems writing data. No sub-
data has been lost, but there sequent
has been a reduction in the tables
capacity of the tape.
3 Hard W The operation has stopped See
Error because an error has oc- sub-
curred while reading or sequent
writing data which the drive tables
cannot correct.
4 Media C Your data is at risk: See
1. Copy any data you re- sub-
quire from this tape. sequent
2. Do not use this tape tables
again.
3. Restart the operation
with a different tape.
5 Read C The tape is damaged or the See
Failure drive is faulty. Call the tape sub-
supplier helpline. sequent
tables
6 Write C The tape is from a faulty See
Failure batch or the tape drive is sub-
faulty: sequent
1. Use a good tape to test tables
the drive.
2. If the problem persists,
call the tape drive supplier
helpline.
7 Media W The tape cartridge has The media On tape
Life reached the end of its useful has eject
life: exceeded
1. Copy any data you need its
to another tape specified
2. Discard the old tape. life
(NR)
8 Not Data W The tape cartridge is not Load of On tape
Grade data-grade. Any data you Non data eject
back up to the tape is at grade
risk. Replace the cartridge media data
with a data-grade tape. grade
detect
enabled
(N/A)
Write
attempt to
Non data
grade
media data
grade
detect
enabled
(R)
9 Write C You are trying to write to a Write On tape
Protect write-protected cartridge. command eject
Remove the write-protect- is
ion or use another tape. attempted
to a write
protected
tape (R)
10 No I You cannot eject the car- Manual or On lock
Removal tridge because the tape s/w unload removal
drive is in use. Wait until attempted
the operation is complete when
before ejecting the car- prevent
tridge. media
removal
on (R)
11 Cleaning I The tape in the drive is a Cleaning On tape
Media cleaning cartridge. tape en- eject
If you want to back up or countered
restore, insert a data-grade during
tape. backup or
restore
(R)
12 Unsup- I You have tried to load a Attempted On load
ported cartridge of a type which is loaded of of valid
Format not supported by this drive. unsup- format
The cartridge has been ported tape
automatically ejected. tape for- (includ-
mat, e.g. ing
DDS2 in cleaning
DDS1 tape)
drive
13 Snapped C The operation has failed be- Tape On next
Tape cause the tape in the drive snapped in media
has snapped: the drive load
1. Discard the old tape. (NR)
2. Restart the operation
with a different tape.
20 Clean C The tape drive needs clean- See
Now ing: sub-
1. If the operation has sequent
stopped, eject the tape and tables
clean the drive
2. If the operation has not
stopped, wait for it to finish
and then clean the drive.
21 Clean W The tape drive is due for Not
Periodic routine cleaning: Supported
1. Wait for the current
operation to finish.
2. Then use a cleaning
cartridge.
22 Expired C The last cleaning cartridge The Until a
Cleaning used in the tape drive has cleaning valid
Media worn out: tape has clean is
1. Discard the worn out expired carried
cleaning cartridge. (R) out
2. Wait for the current
operation to finish.
3. Then use a new cleaning
cartridge.
30 Hardware C The tape drive has a hard- See
A ware fault: sub-
1. Eject the tape or sequent
magazine. tables
2. Reset the drive (hold the
unload button down for 5
seconds).
3. Restart the operation.
31 Hardware C The tape drive has a hard- See
B ware fault: sub-
1. Turn the tape drive off sequent
and then on again. tables
2. Restart the operation.
3. If the problem persists,
call the tape drive supplier
helpline.
32 Interface W The tape drive has a prob- The drive
lem with the SCSI inter- has
face: identified
1. Check the cables and an
cable connections. interfacing
2. Restart the operation. fault
33 Eject C The operation has failed: Error
Media 1. Eject the tape or recovery
magazine. action
2. Insert the tape or
magazine again.
3. Restart the operation.
34 Download W The firmware download has Firmware
Fail failed because you have download
tried to use the incorrect failed
firmware for this tape drive.
Obtain the correct firmware
and try again.
40 Loader C The changer mechanism is Loader
Hardware having difficulty communi- mech. is
A cating with the tape drive: having
1. Turn the autoloader off trouble
then on. communi-
2. Restart the operation. cating
3. If problem persists, call with the
the tape drive supplier tape drive
helpline.
41 Loader C A tape has been left in the Stray tape
Stray autoloader by a previous left in
Tape hardware fault: loader
1. Insert an empty maga- after
zine to clear the fault. pervious
2. If the fault does not error
clear, turn the autoloader recovery
off and then on again.
3. If the problem persists,
call the tape drive supplier
helpline.
42 Loader W There is a problem with the See
Hardware autoloader mechanism. sub-
B sequent
tables
43 Loader C The operation has failed Tape
Door because the autoloader changer
door is open: door open
1. Clear any obstructions
from the autoloader door.
2. Eject the magazine and
then insert it again.
3. If the fault does not
clear, turn the autoloader
off and then on again
4. If the problem persists,
call the tape drive supplier
helpline.
64
TABLE 2
RAW Retries
Criteria State 1 State 2
1 Read The Tape Drive is having
problems reading data
2 Write The Tape Drive is having SET SET
problems writing data
3 Hard Error A Hard Error has
occurred
4 Media You are advised to copy SET
any data that you need to
another tape and discard
this tape
5 Read Fail You may either have a
damaged tape, or the tape
drive is faulty. Please call
the service engineer
6 Write Fail You may either have a
faulty batch of media, or
the tape drive is faulty.
Please use known good
media or call the service
engineer
20 Clean Now The tape drive heads need SET
cleaning, use a cleaning
cartridge now.
30 Hardware A The tape drive has a
hardware fault, try a soft
reset
31 Hardware B The tape drive has a
hardware fault, try
powering the tape drive
off and then on again
State Change State Machine: States 1/2
Criteria State 1 if >24 hrs from
last clean
State 2 if <24 hrs from
last clean
TABLE 3
Read Retries
Criteria State 1 State 2
1 Read The Tape Drive is having SET SET
problems reading data
2 Write The Tape Drive is having
problems writing data
3 Hard Error A Hard Error has
occurred
4 Media You are advised to copy SET
any data that you need to
another tape and discard
this tape
5 Read Fail You may either have a
damaged tape, or the tape
drive is faulty. Please call
the service engineer
6 Write Fail You may either have a
faulty batch of media, or
the tape drive is faulty.
Please use known good
media or call the service
engineer
20 Clean Now The tape drive heads need SET
cleaning, use a cleaning
cartridge now
30 Hardware A The tape drive has a
hardware fault, try a soft
reset
31 Hardware B The tape drive has a
hardware fault, try
powering the tape drive
off and then on again
State Change Any tape load
Criteria Cycle 121212 etc
Except state 1 if >24 hrs
from last clean
TABLE 4
Read Error Write Error Hardware
Codes: 9X + Codes: 8X + Error Codes:
Criteria Tape Mgmt Tape Mgmt 2nd and
Occurrence 1st 2nd 3rd 1st 2nd 3rd 1st subs
1 Read The Tape
Drive is
having
problems
reading data
2 Write The Tape
Drive is
having
problems
writing data
3 Hard A Hard Set Set Set Set Set Set Set Set
Error Error has
occurred
4 Media You are Set Set
advised to
copy any
data that you
need to
another tape
and discard
this tape
5 Read You may Set
Failure either have a
damaged
tape, or the
tape drive is
faulty.
Please call
the service
engineer
6 Write You may Set
Failure either have a
faulty batch
of media, or
the tape
drive is
faulty.
Please use
known good
media or
call the
service
engineer
20 Clean The tape Set Set
Now drive heads
need
cleaning,
use a
cleaning
cartridge
now
30 The tape Set
Hardware drive has a
A hardware
fault, try a
soft reset
31 The tape Set
Hardware drive has a
B hardware
fault, try
powering
the tape
drive off
and then on
again
State Cln Md Md Cln Md Md Soft Hard
Change Ej Ej Ej Ej Reset Reset
Cycle 123123123etc N/A
pattern Except state 1 if >24 hours from last
clean
TABLE 5
7 6 5 4 3 2 1 0
0 Page Code 0.times.2e
1 Reserved (0)
2 Page Length
3
4 Parameter Code (1)
5
6 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
7 Parameter Length (1)
8 Read Flag
9 Parameter Code (2)
10
11 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
12 Parameter Length (1)
13 Write Flag
14 Parameter Code (3)
15
16 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
17 Parameter Length (1)
18 Hard Error Flag
19 Parameter Code (4)
20
21 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
22 Parameter Length (1)
23 Media Flag
24 Parameter Code (5)
25
26 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
27 Parameter Length (1)
28 Read Failure FIag
29 Parameter Code (6)
30
31 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
32 Parameter Length (1)
33 Write Failure Flag
34 Parameter Code (7)
35
36 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
37 Parameter Length (1)
38 Media Life Flag
39 Parameter Code (8)
40
41 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
42 Parameter Length (1)
43 Not Data Grade Flag
44 Parameter Code (9)
45
46 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
47 Parameter Length (1)
48 Write Protect Flag
49 Parameter Code (0.times.A)
50
51 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
52 Parameter Length (1)
53 No Removal Flag
54 Parameter Code (0.times.B)
55
56 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
57 Parameter Length (1)
58 Cleaning Media FIag
59 Parameter Code (0.times.C)
60
61 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
62 Parameter Length (1)
63 Unsupported Format Flag
64 Parameter Code (0.times.D)
65
66 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
67 Parameter Length (1)
68 Tape Snapped Flag
. . . Parameter Code (xx)
. . .
. . . DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
. . . Parameter Length (1)
. . . xxxxxxxxxxxxxxxxx
99 Parameter Code (0.times.14)
100
101 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
102 Parameter Length (1)
103 Clean Now Flag
104 Parameter Code (0.times.15)
105
106 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
107 Parameter Length (1)
108 Clean Periodic Flag
109 Parameter Code (16)
110
111 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
112 Parameter Length (1)
113 Expired Cleaning Media Flag
. . . Parameter Code (xx)
. . .
. . . DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
. . . Parameter Length (1)
149 Parameter Code (1E)
150
151 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
152 Parameter Length (1)
153 Hardware A Flag
154 Parameter Code (1F)
155
156 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
157 Parameter Length (1)
158 Hardware B Flag
159 Parameter Code (20)
160
161 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
162 Parameter Length (1)
163 Interface Flag
164 Parameter Code (21)
165
166 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
167 Parameter Length (1)
168 Eject Media Flag
169 Parameter Code (21)
170
171 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
172 Parameter Length (1)
173 Download Fail Flag
. . . Parameter Code (xx)
. . .
. . . DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
. . . Parameter Length (1)
. . . xxxxxxxxxxxxxxxxxxxxx
199 Parameter Code (0.times.28)
200
201 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
202 Parameter Length (1)
203 Loader Hardware A Flag
204 Parameter Code (0.times.29)
205
206 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
207 Parameter Length (1)
208 Stray Tape Flag
209 Parameter Code (0.times.2A)
210
211 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
212 Parameter Length (1)
213 Loader Hardware B Flag
214 Parameter Code (0.times.2A)
215
216 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
217 Parameter Length (1)
218 Loader Door Flag
. . . Parameter Code (xx)
. . .
. . . DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
. . . Parameter Length (1)
. . . xxxxxxxxxxxxxxx
319 Parameter Code (40)
320
321 DU DS(1) TSD(0) ETC(0) TMC(0) Res(0) LP(0)
(0)
322 Parameter Length (1)
323 xxxxxxxxxxxxxxx
TABLE 6
7 6 5 4 3 2 1 0
0 Page Code (0.times.1C)
1 Page Length (0.times.0A)
2 Perf Reserved DExcpt Test Reserved LogE IT
3 Reserved MRIE
4 Interval Timer
5
6
7
8 Report Count
9
10
11
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